Dozer blade assembly



Dec. 13, 1960 J GWlNN, JR 2,963,802

DOZER BLADE ASSEMBLY Filed April 17, 1957 INVENTOR. 1266p; fizz/2'71, J3?

DOZER BLADE ASSEMBLY Filed Apr. 17, 1957, Ser. No. 653,438

2 Claims. (Cl. 37144) This invention relates generally to ground working attachments for tractors and more particularly to a dozer blade assembly.

Prior dozer blade assemblies have been objectionable in at least two respects. First of all, during continued use, the curved moldboard surfaces have tended to buckle rearwardly. This buckling was the result of the bulkhead reinforcing constructions which did not provide for a positive connection of the bulkheads both to the rear side of the moldboard and the reinforcing structure arranged rearwardly of the moldboard. In addition, the removable ground engaging blade members provided at the lower ends of the moldboards in prior constructions have been mounted such that on the application of the usual horizontal forces thereto, the lower ends of the moldboards have been bent rearwardly. Various reinforcing structures have been applied to the lower ends of the moldboards in attempts to prevent this buckling but it has been found that such structures usually interfere with normal use of the blade, particularly during back-filling operations.

An object of this invention, therefore, is to provide an improved dozer blade assembly.

A further object of this invention is to provide a dozer blade assembly which is relatively light in weight, compact in construction, and which will provide satisfactory results over a prolonged service life with a minimum of maintenance.

Still a further object of this invention is to provide a dozer blade assembly which is simple to fabricate and assemble, economical to manufacture, and efficient in performing the usual dozer operations.

Further objects, features and advantages of this invention will become apparent from a consideration of the following description, the appended claims and the accompanying drawing in which:

Fig. 1 is a foreshortened rear elevational view of the dozen blade assembly of this invention.

Figs. 2 and 3 are enlarged transverse sectional views looking substantially along the lines 2-2 and 33 in Fig. l; and

Fig. 4 is a diagrammatic side elevational view of a portion of the lower end of the dozer blade assembly of this invention, showing the relation of the forces most commonly applied thereto.

With reference to the drawing, the dozer blade assembly of this invention, indicated generally at 10, is illustrated in Fig. l as including the usual horizontally extending moldboard 12 which is curved in a vertical direction. The moldboard 12 is curved so that its front side 14 is generally concave in a vertical direction and the rear side 16 is provided with upper and lower pairs of pivot pin brackets 18 and 20, respectively, arranged at the ends of the moldboard 12. For mounting the moldboard 12 on the usual tractor mounted C-frame (not shown), the assembly 10 also includes a swivel unit 22 arranged on the rear side of a central portion of the moldboard 12. The details of the swivel unit 22 form :tates Patent 2,963,862 Patented Dec. 13, 1960 no part of this invention and it is, therefore, not described in detail herein.

Secured to the rear side 16 of the moldboard 12 at a position adjacent the top end 24 of the moldboard is a reinforcing channel 26 which extends longitudinally of the moldboard. A dirt shield 28 is mounted on the chan nel 26 and the upper end of the moldboard 12 and extends upwardly therefrom in the usual manner for blocking the rearward travel of material over the top end of the moldboard 12.

A plurality of reinforcing bulkhead plates or ribs 30, spaced horizontally from each other, are secured to a lower end portion 32 of the moldboard 12. The ribs 30 are of an irregular shape, with each rib having a first pair of elongated diverging sides 34 and 36. A third elongated side 38 of a rib 30 extends between the rear ends of the sides 34 and 36 and a fourth short side 40 extends upwardly and forwardly between the front ends of the sides 34 and 36.

As best appears in Figs. 2 and 3, the portion 32 of the moldboard 12 is curved downwardly and forwardly and the side 34 of each rib 30 is similarly curved and secured to the rear side of the portion 32 by welding 42. A base plate 44 is secured by welding 46 to the sides 36 of the ribs 30 and has an upwardly extending rear flange 43 secured to the sides 38 of the ribs 30. A backing angle plate 50 has its lower end 52 secured to the flange 48 on the base plate 44 and extends upwardly and forwardly therefrom and is attached at its opposite end by welding 54 to the rear side 16 of the moldboard 12 at a position above the ribs 30.

A heavy angle member 56 having a pair of legs 58 and 61) has the leg 58 secured by welding 62 to the short fourth sides 40 of the ribs 30. Welding 64 and 66 also secures opposite ends of the leg 58 to the lower ends of the moldboard 12 and the base plate 44, respectively. The other angle member leg 60 is inclined downwardly and forwardly from the front end of the leg 5850 as to constitute a lower extension of the moldboard 12.

It is seen, therefore, that the base plate 44, angle plate 50, and the leg 58 of the angle member 56 cooperate with the moldboard portion 32 to form a longitudinal reinforcing tube at the lower end of the moldboard 12 similar to the tube formed by the channel 26 at the upper end of the moldboard 12. Upright straps 61 are connected to and extend between the channel 26 and the backing angle 50 to connect the reinforcing tube structures. These tube structures at the upper and lower ends of the moldboard 12 of course strengthen the moldboard against twisting andbending. Furthermore, the inclusion of the ribs 30 at spaced intervals within the tube formed by the backing plate 50 and the base plate 44 reinforces the moldboard 12 against inward buckling. This reinforcement is achieved by first welding the ribs 30 to the rear side of the moldboard 12. Following this operation, the base plate 44 is welded to the sides 36 of the ribs 30 and the backing plate 50 is then applied along with the angle member 56. As a result of this sequence of assembly, the desired attachment of the ribs 30 to the moldboard 12 and the reinforcing tube structure at the lower end of the moldboard is insured without maintaining precise tolerances on all of the parts which would be required if the tube was first assembled with the moldboard 12 before the ribs 30 were welded in place.

A ground engaging cutting edge member 70 having separate end portions 72 is secured by bolts 74 to the leg 60 for the angle member 56 to complete the dozer blade construction. The bolts 74 are removable to provide for removal of the cutting edge 70 for replacement pur oses.

As illustrated in Fig. 4, the lower moldboard portion 32 and the base plate 44 are inclined downwardly and forwardly in a converging relation so that imaginary extensions thereof intersect at a point 80, on the rear side of the cutting edge 70 adjacent the lower end thereof. It is, of course, the lower end portion of the cutting edge 70 which receives most of'the forces applied to-the blade assembly 10. during use. Also, most of the impact type forces, such asthose which result from the blade assembly hitting a rock, are applied to the lower end of the cutting edge 70. These forces, of course, represent the maximum forces applied to the assembly 10 and are the forces which must be considered in designing an assembly which will withstand prolonged service.

By locating the point 80 as close as possible to the lower end of the blade, the shear forces, represented by the arrows, 82, applied to the moldboardlZ, the base plate 44 and the ribs 30, arereduced to a minimum. As a, result, only tension or compression forces, represented by the arrows 86 and 88, are transmitted to the moldboard 12 and the base plate 44, respectively. It is apparent that if the force applied to the cutting edge '70, and represented by the arrow 90 in Fig. 4, does intersect the point 80, the shear forces 82 and 84 are zero. Accordingly, by locating the base plate 44 and the mold board portion 32, such that the point 80 is adjacent the lower end of the cutting edge 70, the shear forces 82 and 84 are maintained as close as possible to zero during actual use of the blade assembly 10.

From the above description it is seen that this invention provides a dozer blade construction 10 having a minimum of parts which are readily connected to provide a construction designed to efiiciently withstand the usual forces applied thereto. The arrangement of the heavy angle 56 between the moldboard 32 and the base plate 44 provides the desired intersecting relation of'the moldboard portion 32 and the base plate 44 so that the moldboard 12 is strengthened without any. necessity for encumbering the back side 16 thereof with any interfering Structure. Furthermore, this location of the angle member 56 provides for a spreading apart of the welding 42 and 46 to thus strengthen the attachment of the ribs 30 to the moldboard 12 and the base plate 44. By applying the bulkhead ribs 30 to the back side of the moldboard 12 so that they are Welded both to the moldboard 12 and the base plate 44, any buckling of the moldboard 12 during use is effectively prevented.

Although the invention has been described with respect to a preferred embodiment thereof, it is tobe understood that it is not to be so limited, since changes canbe made therein which are within the scope of the invention as defined by the appended claims.

What is claimed is:

1. A material handling attachment for vehicles comprising a generally upright horizontally extending moldboard having front and rear sides and,terminating at the lower end thereof in a downwardly and forwardly inclined lower end portion, reinforcing means adjacent the lower end of said moldboard extending along the rear side thereof, said reinforcing means including a downwardly and forwardly inclined base plate and a reinforcing member secured to the upper end of said base plate and the rear sideof said moldboard at a position above said base plate, a plurality of horizontally spaced upright reinforcing ribs at the rear side of said moldboard between said reinforcing member and said base plate, each of said ribs having a plurality of sides one of which is welded to the rear side of said moldboard and a second one of which is welded to said base plate, supporting means secured to zt-he lower end of said moldboard and said base plate, and a ground engageable cutting edge member removably mounted on said supporting means.

2. A material handling attachment for vehicles comprising a generally'upright horizontally extending moldboard having front and rear sides and terminating at the lower end thereof in a downwardly and forwardly inclined lower end portion, reinforcing means adjacent the lower end of said moldboard extending along the rear side thereof, said reinforcing means including a downwardly and forwardly-inclined base plate having the lower end thereof spaced from said moldboard lower end portion and a reinforcing member secured to the upper end of said base plate and the rear side of said moldboard at a position above said base plate, a supporting member having diverging legs one of which is secured to and extends downwardly from the lower end of said moldboard end portion and a second one of which extends between said moldboard and said base plate, a plurality of horizontally spaced upright reinforcing ribs at the rear side of said moldboard between said reinforcing member and said base plate, each of said ribs having a plurality of sides one of which is welded to-the rear side of said moldboard and a second one of which is welded to said base plate and a third one of which is welded to said second leg of the supporting member at a position between said moldboard end portion and said base plate, and a ground engageable cutting edge member removably mounted on said one leg of said supporting means, said downwardly inclined base plate and moldboard portion being relatively arranged in planes which intersect adjacent the lower end of said cutting edge member.

References Cited in'the file of thispatent UNITED STATES PATENTS 2,108,466 Allin et al. Feb. 1 5, 1938 2,740,213 Barrett Apr. 3, 1956 2,753,638 Mork July 10, 1956 2,777,222 Allin n- Jan. 15, 1957 Randi. 

